Spark-plug.



SCHMIDT.

SPARK PLUG.

APPLIoATIoN FILED 11.11111, 1911. l

Patglld Jn-30, 1912.

31,-. A /l/ f Unrrnn srarnsriarnnr ernten.

ALBERT SCHMIDT, or FLINT, MICHIGAN, essie-Non To Hannon remmen co., or

FLINT, :niente-AN, A con-ronarren or MICHIGAN.

SPARK-PLUG.

To all who/m t may concern Be it known that l, ALBERT Sci-Dinar, a citizen of the United States of America, residing at Flint, in the county of Genesee and State of Michigan, have invented certain new and useful ln'iproveinents in Spark- Plugs, of which the following a specification, reference being had therein to the accompanying drawings.

rllhis invention relates to improven'ients in spari; plugs and its object is to provide a simple and cheap construction designed to prevent the breaking ot the parte by contraction and expansion and further to provide certainother new and useful features in the construction and arrangement of part-s all as hereinafter more fully described reference being had to the accompanying drawing in which L n Figure 1 is a side elevation of a device einbodying the invention; Fig. Q, a vertical section through the same; Fig. 3 is a transverse lsection of a seating collar detached; and Fig. fl is a similar View ot the collar atter having been used in the plug.

fis shown in the drawings 1 is a metal bushing formed with an externally screwtlireaded end adapted to be screwed -into an opening in an engine cylinder vby means of a hexagonal head on its outer end. rlhe bushis 'formed nf'ith an atrial bore 2 which is enlarged at the upper end or head of the bushing to form a chamber 3, the wall ot' which is formed with a serewthread to receive the screwthreaded end ot' a ring nut 4. he bottom or inner end'of the chamber 3 forms an inclined seat 5 for a ring or collar 6 which is similarly tapered or inclined at its lower side to tit the seat. This collar is also formed with a .tl-ange 7 extending upwardly therefrom at vits inner edge around the opening theretlnougli.

An insulating plug formed ot' porcelain oi" other suitable material is made in three parts and secured within the bushing, the lower or inner part 8 being .tapered to extend downwardly through the collar 6 in the axis et the bere 2 of the bushing. Near Sto.

rateatea aan. so, raie.

Serial No. 624,334.

ment' of the ring Ll with the upper end of said Harige, this shoulder willbend or form the flange outwardly as shown in Fig. t, so 'that the flange on the collar will form a closely lit-ting seat for the shoulder and make a tight oint. v

The upper or outer member 10 of the insulating plug is tapered slightly, extending loosely through the ring f1, and near its inner end, is formed with an annular lshoulder 11 adapted to be engaged by'a corresponding shoulder formed on the inner side of said ring. The parte are so proportioned that the said member l() will be loosely held by the ring, ample space being provided in the ring to permit the free expansion of said member. The members '8 and 10 of the plug are each formed with an axial bore and this bore is enlarged at the inner end of vthe outer member 10 and at the outer end of the inner member 8, said enlargements together forming an axial chamber'12 in said meinbers to receive a tubular member 13 also formed of insulating material. The insulating member 13 of the plug tits loosely within its chamber and connects the two members 8 and 10, holding the same in axial alineinent so that when so connected they form acontinuous insulating plug extending completely through the bushing. Said tubular member thus serves to loosely interlock said inner and outer members, breaking joints therewith and preventing shortcircuiting.

A Wire 14 extends through the axial bore platinum wire 15 which is secured within a hole in the inner end of the bushing and bent at right angles toward the projecting end of the wire 14.

In the axial bore of the outei member 10 of the insulating plug is a rod 16 which is screwthreaded at its outer end and provided with a hea-d 17 at its inner end to engage the end of the chamber 12. A binding nut 18 on the outer end of the rod holds the same in place and also'serves as a means for attaching an electrical conductor there- Electrical connection is made between the outer end of the Wire 14 and the head 17 by means of a coiled spring 19, within the chamber 12 attached to the upper end 30 outer member abutting the outer end of the of the Wire and engaging the head.' This spring serves also to hold the member 13 seated upon the bottom of its chamber 12 in the inner member of the plug and the outer member raised with its shoulder 11 in Contact withrtlie shoulder on the rings to.

prevent excessive vibration of these members.'

Byforminggthe insulating plug in three parts'as shown, the inner or intermediate member 13 serves to interlock the outer parts, forming a connection between them to hold the 'same in alinement and prevent short circuiting,and the liability of breakage from expansion or contraction is reduced to a minimum, while, should one of the parts be accidentally broken, it will not be necessary torenewv the entire plug. By forming the collar 6 with a' single upwardly extending ilange of sotty metal which is easily formed over by the engagement of the plug therewith, a tight joint is formed and the langemay be of such a width a's to give a Wide seat.for the plug which will irmly hold 'thesame in place.

' Having thus fully described my invention .'l. In a spark plug, the combination with a bushing, of an insulating member. in the bushing comprising an inner (member, an

inner member, and an intermediate member loosely engaging the inner member at one end and extending across theplane oftheA abutting ends into engagement with the outer member and holding said members in axial alinement.

2. In a spark plug, the combination with a bushing, of an. insulating member in the bushing comprisingv an inner insulating member, an outer insulating member abutting the outer end of the inner member, said members being formed with an axialv chamber intheir abutting ends and an -axial bore, and an insulating member within said cham- `ber connecting said inner and outer members and an electrode extending through the bore of the inner member and said tubular member,

3. In a spark plug, the combination with a bushing, of an insulating member in the bushing comprising an .inner insulating member having an axial bore and an annular shoulder to seat within the bushing, an outer insulating member having an annular shoulder Vand an axial bore, the bores of said members being enlarged at the adjacent ends of said members to form an axial-chamber,r

a tubular insulating member within the said chamber connecting said members to hold the same in axial alinement` an velectrode extending through the bores of said members.

and said tubular member and an annular member with'in the outer end of the bushing Ain engagement with the outer end of the inner insulating member to hold the same" seated and loosely engagingthe shoulder insulating member having an annular shoul 'deito seat Within the bushing and formed with an axial bore, an outer insulating member formed with an annular shoulder and l having van axial bore, an externally screwthreaded ring nut to engage the chamber and the upper end of the innerinsulating member at its inner end, said ring nut being formed with'a shoulder to engage the shoul-,

der on the outer insulating member, and

means within the axial bore of the insulating members vfor yieldingly holding the outer insulating member in engagement with the( shoulderon the ring nut.

5. In a spark plug, the combination with a bushing, of an insulating member within the bushing comprising an innermember having an axial bore which is enlarged at l the upper end of said members, an'outer member formed with an axial bore which 1s enlarged at the lower end of said member,l

the-enlargements of the bores in the adjacent ends of said members forming an axial chamber, av tubularinsulating member in said chamber engaging the bottom therein?,` 1n the inner vmember, a wire extending;

through the bore of said inner member and said tubular member, and a coiled spring Within the chamber between its upper end and the upper end of said tubular member therein.

reefl 6. In a spark plug, the combination, o'

bushing having an internally screwthr-eaded Y chamber in itsouterend, an inner insulating lmember adapted to seat within said chamber and formed with an axial bore and an axial chamber in its upper end, an'outer insulating 'member formed with an annular shoulder and an axial bore, a ring nut screwed into'the chamber with its inner end ics iii)

engaging the outer end of the inner member and formed with an annular shoulder to engage the shoulder on. the outer member, a spring within the axial chamber adapted to hold thejouter membery in engagement with the shoulderi'on the ring nut, and an electrode extending through 'the axial bore of said members.l

7. 'In a spark plug, the combination of a vbushing having an internall screivthreaded chamber in its outer end, an inner insulating member adapted to seat within said chamber and formed with an axial bore and an axial chamber in its outer end, an outer insulating member formed with an annular shoulder and an axial bore and a chamber in its inner end, a ring nut screwed into the chamber Withits inner end engaging the'outer end of the inner member and formed with an annular shoulder to engage its shoulder on the Outer member, ,e tubular insulating member in the chamber of said inner and outer members, a, Wire forming an electrode extending through the bore of the inner member and the tubular member, a rod in the bore of the outer member, and a coiled spring between the upper end of the tubular member and the end of the chamber in the outer member, and forming an electrical l0 connection between said Wire and rod.

In testimony whereof IV aHiX my signature in presence of tWo Witnesses.

, ALBERT SCHMIDT.

Witnesses:

B. DE GUICHARD, F. J. UTLEY. 

